Sodium intake and compliance with dietary sodium modification are typically assessed using a 24-h urine collection analyzed using flame photometry, but this is inconvenient. Spot urine samples have been investigated as alternatives to 24-h collections, but their accuracy is poor. Since sodium and chloride are present in equal concentrations in dietary salt, chloride test strips may provide a suitable proxy for at-home measurement of urine sodium concentrations. We aimed to determine whether (i) chloride test strips provide a reliable measure of urinary sodium compared to the gold standard flame photometry and (ii) multiple spot samples accurately reflect 24-h urine sodium. We recruited 43 participants (19 males) aged 23.6 ± 0.6 years to complete multiple consecutive spot samples (morning and evening) along with a 24-h urine sodium collection. Urine 24-h sodium estimates using chloride test strips (114.6 ± 7.5 mmol/day) were highly correlated (r = 0.900, p < 0.0001) with flame photometry (121.1 ± 7.7 mmol/day) with a bias of −6.53 ± 22.2 mmol/day. Use of a three-spot sample average (both morning and evening spot samples) with a correction factor applied (122.9 ± 4.1 mmol/day) provided a good approximation of 24-h sodium measured by flame photometry (125.6 ± 9.0 mmol/day), with a bias of −2.55 ± 43.9 mmol/day. Chloride test strips applied to a 24-h urine collection provide a highly accurate measure of urinary sodium excretion, permitting convenient at-home sample collection and analysis. Their application to multiple spot samples provides a reasonable approximation of sodium excretion that can be used to conveniently monitor attempts at dietary sodium manipulation, without the inconvenience of completing a 24-h urine sample.

通常使用使用火焰光度法分析的 24 小时尿液收集来评估钠摄入量和对膳食钠调整的依从性，但这很不方便。现场尿液样本已被研究作为 24 小时收集的替代品，但其准确性很差。由于钠和氯化物在膳食盐中的浓度相等，因此氯化物试纸可以为家庭测量尿钠浓度提供合适的代理。我们旨在确定 (i) 氯化物试纸与金标准火焰光度法相比是否提供可靠的尿钠测量值，以及 (ii) 多点样本准确反映 24 小时尿钠。我们招募了 43 名年龄为 23.6 ± 0.6 岁的参与者（19 名男性）来完成多个连续的现场样本（早上和晚上）以及 24 小时尿钠收集。r  = 0.900, p  < 0.0001) 火焰光度法 (121.1 ± 7.7 mmol/day)，偏差为 -6.53 ± 22.2 mmol/day。使用三点样本平均值（早上和晚上的点样本）并应用校正因子（122.9 ± 4.1 mmol/天）提供了通过火焰光度法测量的 24 小时钠的良好近似值（125.6 ± 9.0 mmol/天） ，偏差为 -2.55 ± 43.9 mmol/天。应用于 24 小时尿液收集的氯化物测试条可提供高度准确的尿钠排泄量测量，允许方便的家庭样品收集和分析。它们对多点样本的应用提供了钠排泄的合理近似值，可用于方便地监测饮食钠控制尝试，而无需完成 24 小时尿样的不便。